Advanced Materials Research Vol. 676

Abstract: Carried on finite element analysis using the UG software to finally carry on the fatigue life’s computational method to carry on the exploration and the research. when carrying on the finite element stress strain analysis to the piston pin, used the different analysis method, because the piston pin’s quality is very slightly oppositeing to the piston quality, produces the force of inertia is very small, the counter stress computed result is not very obvious, therefore to piston pin finite element analysis we uses conventional algorithm that infliction boundary condition.

Abstract: CNC machine, especially CNC milling machine, is the main production equipment in the industries of mechanics, iron and steel, automobile manufacturing and so on. However, the errors are the main constraints to the processing quality and the precision measurement of CNC machine. Based on the multi-body system theory, the article models the error of Siemens CNC milling machine and kinematic. In terms of the analysis of the error model, it is argued that the processing precision of CNC milling machine can be improved through controlling and compensating the error in the process of installation and manufacturing.

Abstract: Nowadays vibration of hull caused by the shaft surface roughness has caught attentions all over the world. In this paper we conducted a brief analysis on this project based on the contact theory and FEM. Firstly, we calculated the contact force based on numerical simulation and contact theory. Then we analyzed the effects of speed and shaft surface roughness on the hull vibration. Results show that the effect of shaft surface roughness on the hull vibration is greater than that of speed. But when the frequency of contact force gets close to the natural frequency of hull, the effect of speed becomes obvious. These conclusions have large significance on the selection of shaft and the design of hull.

Abstract: S-doped TiO2 nanomaterials were prepared via hydrothermal synthesis method using tetrabutyl titanate. Kinetics of S-doped TiO2 catalyzing phenol was researched by analysising the influence of initial phenol concentration, initial phenol pH value on photochemical catalysis speed. The results indicated that the value of K decreased with the rising of phenol concentration. The influence of initial solution pH was exsiting an optimal value. When pH value was 4, photocatalytic rate was maxium, corresponding K was 0.17983 min-1.

Abstract: To study vibration signals processing mechanics and the analysis method of the numerical control machine. vibration signals analysis method include time and frequent domain analysis: the time domain analysis mainly has the statistical analysis and the correlation function analysis. frequency domain analysis include spectral analysis, cepstrum analysis, data envelopment analysis. vibration signals pretreatment is the most commonly used and effective method on the mechanical device condition monitor and the failure diagnosis.

Abstract: With the constructing project of Shengli Bridge as the background, this paper presents the measured stress and deformation data of main arch rib during the process of full framing scheme. The measured data are compared with the computation results.And the mechanical behaviors of the arch bridge were studied to reveal the changing tendency of stress and displacement of the main arch construction completed to completion stage. The analysis results show that the stress and the displacement of the key structures are in a reasonable range and meet the design requirements during the process of the construction process.

Abstract: By the setting torsional and lateral displacement function of sidewise buckling of two-hinged circular arch under concentrated force, the single-arch structure's bending, torsional deformation and external force potential can be constructed. An analytical solution for the lateral critical buckling load of two-hinged arch is first deduced by using the energy method; the results are also compared and analyzed by the finite element method. The results show that the analytical solution of single arch’s lateral critical buckling load is in good agreement with the finite element numerical solution, and the validity of the formula is proven.

Abstract: A transformer is a critical device in an electrical power system substation. Monitoring its condition, including insulation material statuses, is imperative. This article discusses the information modeling techniques of IEC61850 and modeling steps of condition-monitoring IED, analyzes the reporting service, focuses on the characteristics of transformer condition monitoring, rationally develops and makes use of logical nodes and data in the IEC61850 standard, conducts modeling for the actual intelligent electronic device (IED) of transformer condition monitoring and describes the model with substation configuration description language (SCL). The configuration file of this model has passed the test done with standard syntax (Schema mode).

Abstract: Doubly-fed Induction Generator (DFIG) is an important equipment in electrical power system. Operation state of DFIG is complex: it works at subsynchronism, synchronization and hypersynchrony state. Electromagnetic field is various. There is winding on stator and rotor, it’s more possible for fault to happen. Text discuss structure of DFIG, finite element method (FEM) model including stator rotor and air-gap is created, typical magnetic field is calculated including normal operation state, turn-to-turn and single-phase short-circuit happened, result is analysed, distribution discipline of multiple magnetic field is obtained. It provide the evidence to early failure prediction, basic data to develop and design high-capacity generator, optimize structure and magnetic field analysis of DFIG.

Abstract: The low-frequency oscillation is one of the most important reasons that affects the stability of the power system. Under the background of building a unified and strong smart grid, the scale of the power system will continue to expand, the interconnection of systems will be more closely, the structure will be more complex, these factors will further increase the difficulty on the low-frequency oscillation control. This paper summarizes the methods to analysis low frequency oscillation signal, the way that suppresses the low frequency oscillation in electrical engineering. Further, based on smart grid framework, a on-line visualization technology and a self-recovery regulation strategy are proposed to damp low-frequency oscillation.